The   KAWAI   SX-210




The Kawai SX-210 (also manufactured under the brand name of  Teisco) is probably one of the most underrated analog synths ever. Being a true analog machine and holding a set of features which many other single oscillator synths are missing, it is still a mystery why such a great instrument like the SX-210 has never been through the popularity of other equivalent synths like the Juno 60/106 and Polysix for example. Still it is quite rare as not many have been made.

The Kawai/Teisco SX-210 is basically an 8 voice single DCO synth based on the SSM2044 filter chips. It is generally very stable (as you might expect from it, being a DCO synth). The overall sound is very warm, yet not as fat as either the Junos or the poly Korgs.

On the other hand, it does feature an envelope for its filters, which you won't find on "basic" synths like the Juno 60/106. And it sounds like nothing else actually. I was able to nail that VCS3 "Welcome to the Machine" leads quite easily !

The SX-210 is also one of the first to feature an alpha dial, but not like most alpha dial based synths, you won't find any cumbersome menus to hate to deal with ;)

Instead, there is a switch for every function, and a small indicator to present the value for the switch selected. This is a great approach to implement, as you are still able to check into every parameter of a particular preset and read its current value !

The SX-210 is also 8 voice polyphonic, and can be used at 8 single voice, 4 dual voice and 1 eight voice configurations, which means you can stack all 8 oscillators into a one fat lead sound or a mega power chord lead ! Can you do that with your Juno ?! ;)

The LFO can oscillate the DCO section, VCF and VCA, all at the same time ! (use a Polysix and you'll have to decide which of the section you'd like to modulate� no simultaneous LFO action !) It is quite versatile and features a Reverse mode and 3 different waveforms plus a Trigger, as well as an LFO Delay and a Bender. Quite impressive for a single DCO synth, huh ?!

The single DCO section can do PW, PWM, SAW and Sub, and noise as well (non for the Polysix) The SX-210 also has a built in stereo Ensemble effect which is very rich sounding and will "widen up" just about any pad or a string preset very nicely, but I must admit it is not as warm as our well known Polysix Ensemble effect, and generally, far from being versatile as the Chorus/Phaser/Ensample Polysix section. The instrument could do wonders has it had the Polysix effect board ;)

Using the VCF modulation section (KCV / LFO / EG) it is possible to create some really interesting sounds. My SX-210 had two bad 4066 chips at the same place on two different voices, making the EG section going bad, only a few months separating between each incident. So this is where you should first look at when you're starting to experience strange EG behavior !



A rare version of the SX210 with a control panel placed under the keyboard



The SX-210 features only 32 presets and a huge preset name 6 characters display (still non on the Junos and Polysix !) which can be easily accessed from the front panel (check out this interesting version of the 210 with the preset button under the keyboard�). You'll also find the standard tape interface for saving and loading presets, and a set of characters painted above each key so can write preset names.


The most problematic side of the SX-210, which you all already know from other synths (such as the Polysix) is the use of a NiCD battery, which turns into acid which will eat they programmer board of any innocent SX-210 ! Beware and change the battery on your immediately if you haven�t done so !

Unfortunately, the one on mine has leaked a few years ago, and I had to rebuild (!!) the entire circuit around it. The battery is placed just near the EG and Gate sections, so mine played just about any note randomly. I had the same old procedure of scraping all traces, hard wire them by following the layout diagram and change all parts at the area. I converted the battery to Lithium coin cell type, by doing a very small modification to the circuit so the battery is not getting charged. See the links below for the programmer board layout and schematics, but better, replace the battery immediately before you're going to run into this tedious and risky procedure !



This is how the SX-210 sounds like:

(Played on my machine, converted to mp3)


Sound 1                        Sound 5                        Sound 9                       Sound 13

Sound 2                        Sound 6                        Sound 10                     Sound 14              

Sound 3                        Sound 7                        Sound 11                     Sound 15                             

Sound 4                        Sound 8                        Sound 12                     Sound 16                             



More useful SX-210 links:


SX-210 programmer board schematics

SYN-42 schematic diagram

SYN-42 board parts layout


Battery leakage repair procedure � done on a Polysix, as described on Old Crow's site. This is quite similar to the procedure on the SX-210.

On Old Crow's site


Other SX-210 links

The Kawai/Teisco Analog synthesizers Yahoo! discussion group

Kawai SX-210 on

SX-210 close-up pictures at PME Record's site

Teisco / Kawai synth page

S.O.S article about Teisco / Kawai SX synths and history

Kawai  SX-240 sound samples on Music Machines





For any suggestions please feel free to contact me at gil_we(at)










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